Nowadays, the electroencephalography (EEG)-based wheelchair driving system, one of the major applications of brain-computer interface (BCI), that allows an individual with mobility impairments to perform daily living activities independently. In this context, user's intention identifying methods were developed by several research groups using various paradigms for the wheelchair driving. In this study, we use a steady-state somatosensory evoked potential (SSSEP) paradigm, which elicits brain responses to vibro-tactile stimulation of specific frequencies, for a user's intention identification to driving a wheelchair. The main focus of this study is to validate an effectiveness of our SSSEP-based wheelchair driving system via an online experiment with more challenging tasks than our recent study. In our system, a subject concentrated on one of vibro-tactile stimuli (attached on left-hand, right-hand, and foot) selectively for driving wheelchair (corresponding to turn-left, turn-right, and move-forward). Five healthy subjects participated in the online experiment, and the experimental results show that our SSSEP paradigm is suitable to EEG-based intelligent wheelchair driving system.